And here is a nice model from Choi and the usual suspects (but with no hydrology.) They project that 79N is not going to do tricks, but Zach is going to retreat until it hits a stabilizing ridge 30 km. upstream.
"Our model suggests that 79North will retreat slowly over the next century, whereas ZI will lose its floating ice tongue completely and retreat rapidly for 70 years. After 70 years, ZI will stabilize 30 km upstream of its current position on a topographic ridge. Frontal melt rates need to reach 6 m/day in the summer to dislodge the glacier from this ridge. ZI will then continue a fast and unstoppable retreat, contributing more than 16.2 mm to global sea level rise by 2100."
"ZI will continue to retreat 30 km upstream, and become a grounded tidewater glacier, until it reaches a stabilizing ~200-m step in bed topography. Our simulations show that ZI is in a state of unstoppable retreat that does not depend significantly on ocean forcing, but is due to its current internal dynamics, which is mainly controlled by the bed topography. This retreat will stop once the ice front reaches this stabilizing ridge in the bed topography. An increase in the frontal melt-rate up to 6 m/day in the summer would be necessary in order to trigger a further retreat inland, and this amount of oceanic forcing, while significant, remains within the range of possible scenarios."
doi: 10.1002/2017GL075174
I attach figs 2a and 3. 2a is the control (unperturbed ocean melt)
sidd